A catalyst for preparing triethylamine by coal-based ethanol hydrogenation and a preparation method and application thereof

Abstract

This invention discloses a catalyst for the hydroamination of coal-based ethanol to triethylamine, its preparation method, and its application. The catalyst includes a support and an active component, cobalt, supported on the support, wherein the active component accounts for 10-30% of the catalyst mass; the support is rod-shaped alumina. The catalyst prepared by this invention fully utilizes the high-temperature complexation of lysine and cobalt nitrate. Simultaneously, the rod-shaped morphology of the alumina effectively improves the dispersion of the active metal. After hydrogen reduction, the reduced cobalt is more uniformly distributed in the rod-shaped alumina, making it less prone to agglomeration during the reaction. This facilitates the diffusion of reactants and products within the catalyst and enhances the catalyst's reactivity. When used for the amination of coal-based ethanol to ethylamine, it exhibits high selectivity for triethylamine.

Description

Technical Field

[0001] This invention belongs to the field of catalyst technology, specifically relating to a catalyst for the hydroamicization of coal-based ethanol to triethylamine, its preparation method, and its application. Background Technology

[0002] Ethylamine is a derivative formed by replacing the hydrogen atom of an ammonia molecule with an ethyl group. It mainly includes monoethylamine, diethylamine, triethylamine, etc. It is an important fine chemical intermediate that can react with a variety of compounds to form derivatives. It is widely used in pharmaceuticals, pesticides, chemical auxiliaries, military industry and new energy industries.

[0003] In recent years, with the continuous increase in my country's lithium battery production capacity, the demand for ethylene carbonate and the new lithium salt LiFSi, which are closely related to triethylamine, has increased significantly, resulting in a surge in the market demand for triethylamine.

[0004] Currently, ethylamine is mainly obtained globally through the hydroamination of bioethanol. However, my country's bioethanol production is limited and expensive. The successful development and industrial production of coal-based ethanol (>4 million tons / year), which is cheaper, provides a raw material guarantee and price advantage for the implementation of this project.

[0005] Ethylamine is prepared by a hydrogenation-pressurized reaction of ethanol and liquid ammonia, followed by separation to produce the final ethylamine product. This process offers advantages such as no side reactions, high product quality, low energy consumption, and the ability to simultaneously produce monoethylamine, diethylamine, and triethylamine. Currently, cobalt- and / or nickel-based catalysts used for the hydrogenation-amination of ethanol to prepare ethylamine are typically supported on irregularly shaped alumina and / or silica.

[0006] Chinese patent CN1436596A provides a low-grade aliphatic amine catalyst, in which cobalt, calcium and other active components are supported on a carrier, with the active components accounting for 10-50% of the catalyst weight. The preparation process of this catalyst is complex and the selectivity is not ideal. Chinese patent CN101869836A provides a low-grade aliphatic amine catalyst, preparation method and application. The catalyst uses alumina with irregular morphology as a carrier, and the active components include: (1) Co, with a content of 10-50%; (2) at least one of Ce, Nd, Pr and Gd, with a content of 0.01-5%; (3) at least one of Cr, Ba, Ag, Mn, Ti, Ge and Zr, with a content of 0.01-10%.

[0007] Chinese patent CN112044447A discloses a catalyst, preparation method, and application for the synthesis of monoethylamine. The catalyst comprises irregularly shaped alumina particles and cobalt, palladium, and rhenium deposited on the surface of the alumina particles. When producing monoethylamine by hydroamination of ethanol, the selectivity of monoethylamine is greater than or equal to 86% (ethanol conversion greater than or equal to 61%, ethylamine selectivity greater than or equal to 99.9%), while the selectivity of triethylamine is lower.

[0008] Chinese patent CN112691677A discloses a catalyst for the preparation of ethylamine by hydroammoniation of ethanol, its preparation method, and its application. The catalyst contains 5-25% Ni, 0.5-30% Sn, and 55-94.5% support (at least one of alumina, silicon dioxide, zirconium oxide, and titanium dioxide with irregular morphology). The selectivity of the products monoethylamine, diethylamine, and triethylamine is about 18%, 54%, and 28%, respectively, with the triethylamine showing a lower selectivity.

[0009] For the hydroamylation of coal-based ethanol to produce triethylamine, impurities such as esters, polymers, and pyridine bases in coal-based ethanol can affect the reaction performance of the catalyst. Therefore, it is of great significance to develop catalysts that are resistant to impurities, operate at low temperatures, are highly active, and have high selectivity for triethylamine. Summary of the Invention

[0010] To address the shortcomings of existing technologies, this invention provides a catalyst for the hydroamination of coal-based ethanol to triethylamine, its preparation method, and its application. When the catalyst is used for the hydroamination of coal-based ethanol to triethylamine, the product triethylamine exhibits high selectivity.

[0011] A catalyst for the hydroamicization of coal-based ethanol to triethylamine, the catalyst comprising a support and an active component cobalt supported on the support, the active component accounting for 10-30% of the catalyst mass; the support is rod-shaped alumina.

[0012] Preferably, the aspect ratio of the rod-shaped alumina is 5-30.

[0013] The preparation method of the catalyst for the hydroamication of coal-based ethanol to triethylamine is as follows: the precursor of the active component and lysine are dissolved in water, and the mixture is stirred and reacted at 120-150℃ for 2-5 hours in a closed environment. After drying, calcination, reduction, cooling, tableting, and sieving, the catalyst is then precipitated.

[0014] Preferably, the mass ratio of the precursor of the active component to lysine is 1:(0.1-0.5).

[0015] Preferably, the reduction is carried out in a hydrogen atmosphere at 400-500°C for 10-30 hours.

[0016] Preferably, the precursor of the active component is cobalt nitrate.

[0017] Preferably, the stirring speed is 20-30 rpm.

[0018] Preferably, the calcination conditions are calcination at 400-550°C in air for 2-5 hours.

[0019] A method for producing triethylamine by hydroammoniation of coal-based ethanol: a catalyst is packed in a fixed-bed reactor and reduced at 230-250°C for 3-8 hours in a hydrogen atmosphere, then reactants are introduced and reacted at a reaction temperature of 150-200°C and a reaction pressure of 1.2-2.0 MPa; the reactants are coal-based ethanol, hydrogen, ammonia and diethylamine.

[0020] Preferably, the molar ratio of coal-based ethanol, ammonia, and diethylamine is 1:(0.3-1.2):(0.4-6.5), and the hydrogen in the reaction raw materials accounts for 50-90% of the total volume of the reaction raw materials; the mass hourly space velocity (WHSV) of the coal-based ethanol is 0.08-0.3 h⁻¹. -1 .

[0021] Preferably, the impurity content in the coal-based ethanol is ≤8000 ppm, and the impurities include ester compounds, polymers and pyridine bases, and the content is by mass.

[0022] Advantages of this invention: The catalyst prepared in this invention fully utilizes the high-temperature complexation of lysine and cobalt nitrate. At the same time, the rod-shaped morphology of alumina can effectively improve the dispersion of active metals. After hydrogen reduction, the reduced cobalt is more evenly distributed in the rod-shaped alumina, making it less prone to agglomeration during the reaction. This is beneficial for the diffusion of reactants and products in the catalyst and for improving the catalyst's reaction activity. When used for the amination of coal-based ethanol to produce ethylamine, it exhibits high selectivity for triethylamine. Detailed Implementation Example 1

[0023] 1. A catalyst for the hydroamicization of coal-based ethanol to triethylamine, the catalyst comprising a support and an active component cobalt supported on the support, the active component accounting for 20% of the catalyst mass; the support being rod-shaped alumina with an aspect ratio of 10; 2. The catalyst is prepared as follows: Cobalt nitrate and lysine were mixed at a mass ratio of 1:0.3 to form a mixture. Three times the mass of water was added to the mixture to form a transparent solution. The solution was placed in a reaction vessel and stirred at 30 rpm for 3 hours at 135°C in a sealed environment. The solution was then dried at 120°C for 6 hours, calcined at 500°C in air for 2 hours, and reduced at 500°C in hydrogen atmosphere for 10 hours. After cooling, the solution was compressed into tablets and passed through a 10-20 mesh sieve. Example 2

[0024] 1. A catalyst for the hydroamication of coal-based ethanol to triethylamine, the catalyst comprising a support and an active component cobalt supported on the support, the active component accounting for 10% of the catalyst mass; the support being rod-shaped alumina with an aspect ratio of 5; 2. The catalyst is prepared as follows: Cobalt nitrate and lysine were mixed at a mass ratio of 1:0.1 to form a mixture. Three times the mass of water was added to the mixture to form a transparent solution. The solution was placed in a reaction vessel and stirred at 20 rpm for 5 hours at 120°C in a sealed environment. The solution was then dried at 120°C for 6 hours, calcined at 400°C in air for 5 hours, and reduced at 400°C in hydrogen atmosphere for 30 hours. After cooling, the solution was compressed into tablets and passed through a 10-20 mesh sieve. Example 3

[0025] 1. A catalyst for the hydroamination of coal-based ethanol to triethylamine, the catalyst comprising a support and an active component cobalt supported on the support, the active component accounting for 20% of the catalyst mass; the support being rod-shaped alumina with an aspect ratio of 20; 2. The catalyst is prepared as follows: Cobalt nitrate and lysine were mixed at a mass ratio of 1:0.4 to form a mixture. Three times the mass of water was added to the mixture to form a transparent solution. The solution was placed in a reaction vessel and stirred at 25 rpm for 3 hours at 140°C in a sealed environment. The solution was then dried at 120°C for 6 hours, calcined at 450°C in air for 3 hours, and reduced at 420°C in hydrogen atmosphere for 15 hours. After cooling, the solution was compressed into tablets and passed through a 10-20 mesh sieve. Example 4

[0026] 1. A catalyst for the hydroamicization of coal-based ethanol to triethylamine, the catalyst comprising a support and an active component cobalt supported on the support, the active component accounting for 30% of the catalyst mass; the support being rod-shaped alumina with an aspect ratio of 30; 2. The catalyst is prepared as follows: Cobalt nitrate and lysine were mixed at a mass ratio of 1:0.5 to form a mixture. Three times the mass of water was added to the mixture to form a transparent solution. The solution was placed in a reaction vessel and stirred at 30 rpm for 2 hours at 150°C in a sealed environment. The solution was then dried at 120°C for 6 hours, calcined at 550°C in air for 4 hours, and reduced at 450°C in hydrogen atmosphere for 25 hours. After cooling, the solution was compressed into tablets and passed through a 10-20 mesh sieve.

[0027] Comparative Example 1 The carrier is alumina with irregular morphology, and everything else is the same as in Example 1.

[0028] Comparative Example 2 In the preparation method, the reaction condition "stirring at 30 rpm for 3 hours at 135°C" is replaced with "standing and impregnating at 70°C for 3 hours", and the rest is the same as in Example 1.

[0029] Comparative Example 3 Lysine was not added during the preparation process, but everything else was the same as in Example 1.

[0030] Catalytic performance evaluation A method for producing triethylamine by hydroamination of coal-based ethanol: A catalyst is packed into a reaction tube of a fixed-bed reactor with a diameter of 9 mm and a catalyst loading of 8 g. The catalyst is then reduced at 230-250°C for 3-8 h in a hydrogen atmosphere. Reaction feedstock is then introduced, and the reaction is carried out at a temperature of 150-200°C and a pressure of 1.2-2.0 MPa. The reaction feedstock consists of coal-based ethanol, hydrogen, ammonia, and diethylamine, wherein the molar ratio of coal-based ethanol, ammonia, and diethylamine is 1:(0.3-1.2):(0.4-6.5), and the volume ratio of hydrogen to the reaction feedstock is 50-90%. The mass hourly space velocity (WHSV) of the coal-based ethanol is 0.08-0.3 h⁻¹. -1 The impurity content in the coal-based ethanol is ≤8000 ppm, and the impurities include ester compounds, polymers, and pyridine bases. The products were analyzed using an Agilent 7890A GC. Specific reaction conditions, the conversion rate of coal-based ethanol, and the selectivity of triethylamine are shown in Table 1. Both ethanol conversion and triethylamine selectivity are calculated based on weight: The ethanol conversion rate is calculated as follows: , Among them, X 乙醇 The conversion rate of coal-based ethanol is expressed in units of 100%; m 乙醇进 The mass of coal-based ethanol in the reaction feedstock is expressed in grams (g); m 乙醇进 The mass of coal-based ethanol in the reaction product is expressed in grams. Triethylamine selectivity: ; Among them, S 三乙胺 The selectivity of triethylamine is expressed in units of 100%; m 产物中三乙胺 The mass of triethylamine in the product is expressed in grams (g); m 产物乙基胺总量 The mass of ethylamine in the reaction product is expressed in grams; m 原料二乙胺 The mass of diethylamine in the reaction feedstock is expressed in grams. Table 1 Reaction conditions and results

[0031] Therefore, compared with the cobalt catalyst supported on an alumina support with irregular morphology (Comparative Example 1), the cobalt catalyst supported on a conventional impregnated rod-shaped alumina support (Comparative Example 2), and the cobalt catalyst supported on a rod-shaped alumina support synthesized without ammonium lysate solvent (Comparative Example 3), the catalyst provided by the present invention can significantly improve the selectivity of triethylamine produced by the hydroammoniation of coal-based ethanol to triethylamine, as shown in Examples 1-4.

Claims

1. A catalyst for the hydroammoniation of coal-based ethanol to triethylamine under hydrogen, characterized in that: The catalyst includes a support and an active component, cobalt, supported on the support, wherein the active component accounts for 10-30% of the catalyst mass; the support is rod-shaped alumina.

2. The catalyst for the hydroamination of coal-derived ethanol to triethylamine according to claim 1, characterized in that: The aspect ratio of the rod-shaped alumina is 5-30.

3. The process for the preparation of the catalyst for the hydroamination of coal-based ethanol to triethylamine according to claim 1, characterized by the fact that: The preparation method is as follows: the precursor of the active component and lysine are dissolved in water, and the mixture is stirred and reacted at 120-150℃ for 2-5 hours in a closed environment. After drying, calcination, reduction, cooling, tableting, and sieving, the mixture is then saturated.

4. The method of claim 3, wherein the catalyst is prepared by the following steps: (1) mixing the coal-based ethanol with the catalyst precursor; (2) heating the mixture to a temperature of 100- 300°C; (3) maintaining the temperature for 1-10 hours; (4) cooling the mixture to room temperature; and (5) recovering the catalyst. The mass ratio of the precursor of the active component to lysine is 1:(0.1-0.5).

5. The method for preparing the catalyst for the hydroamination of coal-based ethanol to triethylamine according to claim 3, characterized in that: The reduction is carried out in a hydrogen atmosphere at 400-500℃ for 10-30 hours.

6. The method for preparing the catalyst for the hydroamination of coal-based ethanol to triethylamine according to claim 3, characterized in that: The precursor of the active component is cobalt nitrate.

7. The method for preparing the catalyst for the hydroamination of coal-based ethanol to triethylamine according to claim 3, characterized in that: The stirring speed is 20-30 rpm.

8. The method for preparing the catalyst for the hydroamination of coal-based ethanol to triethylamine according to claim 3, characterized in that: The calcination conditions are as follows: calcination at 400-550°C in air for 2-5 hours.

9. A method for producing triethylamine by hydroamination of coal-based ethanol, characterized in that: The catalyst is loaded into a fixed-bed reactor and reduced at 230-250°C for 3-8 hours in a hydrogen atmosphere. Then, the reactants are introduced and the reaction is carried out at a reaction temperature of 150-200°C and a reaction pressure of 1.2-2.0 MPa. The reactants are coal-based ethanol, hydrogen, ammonia and diethylamine. The catalyst is the catalyst described in claim 1.

10. The method for producing triethylamine by hydroamination of coal-based ethanol according to claim 9, characterized in that: The molar ratio of the coal-based ethanol, ammonia gas and diethylamine is 1:(0.3-1.2):(0.4-6.5), the volume ratio of hydrogen in the reaction raw material to the reaction raw material is 50-90%; the mass space velocity of the coal-based ethanol is 0.08-0.3h -1 .

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